Oh josia, that's such a horrible situation to be in, I really feel for you. I have been in a similar situation myself, and also had the thought that I would have left him, if he'd been my partner rather than my son. :(
The trouble is, he won't just go away. And he is now of an age where you can't control his behaviour, he has to control himself.
You have a problem because he isn't controlling himself. That might be because he doesn't recognise his bad behaviour, or it might be because he doesn't want to make the effort. You may be able to have some influence, for instance by challenging bad behaviour and telling him when he is being rude, disrespectful, selfish, aggressive, etc. Or you can try to motivate him to make the effort (bribery, threats, etc.) But you can't make him do anything - he has to do that himself.
However, you can control and change your own behaviour and reactions. If you do an advanced search and look through past discussions, you'll find me and many others giving very similar advice:
- Detach, detach, detach! A lot of what they say feels very personal, but it isn't. Some teens just seem to go thru a phase if being foul as part of distancing themselves from you and convincing themselves they can manage without you.
If you realise this, and create a bit of emotional distance yourself, it really seems to help.
- You really only have two options: kick him out or hang on in there. If you don't want to kick him out, you have to hang on in there. If you can't hang on, you'll have to kick him out. Both options are incredibly hard, it seems to me, but it helps if you work out your 'bottom line' - the things you absolutely cannot tolerate - the point at which you will throw him out, if these things happen or don't stop. Once you know your bottom line, you can be clearer with him. You can say, and mean, something like "From now on, I will not put up with X. If you do X, I will do Y. If you do X again, you will have to leave". I found it gave me a lot of strength to work this out... And stick to what I said!
- Don't tolerate violence or threats of violence. You don't say he is violent, but if he is, tell him you will call 999 if he hurts or threatens anyone again. Then do it. People here can give you more advice and opinions if you are in this situation - just say.
- Do pleasant, fun things for yourself. Be kind to yourself. Look after yourself. It isn't a luxury, it's a survival essential! You will cope much better if you have good things to sort of 'balance out' the bad. And you give your DS (and yourself!) a clear message that you believe you are worth respecting and treating well. :)
Good luck... And do hang around here for support... You're not alone, and it definitely helps to know it, and to get ideas from others who have, or have had, similar experiences.